Worm drive unit reassembled

I actually put something back together.  The worm drive unit was an easy fix; all it needed was a good cleaning.  I made sure the shims all went in the way they came out.  I forgot about the breather hole at first, but checked it after re-assembly to insure that the passage was clear.  Nothing worse than having a rear drive unit heat up and push all its oil out the seals.  I've seen this happen on Guzzis before and didn't want my Sunbeam to do the same thing.

Here it is all assembled and waiting to go back on the frame.  Re-installation was easy, I used my method of a threaded rod to compress the springs.  The retaining shaft went in easily as well.  It will probably need a few squirts of grease before going anywhere, but its back on the frame.

I looked at the rear wheel.  Funny all the paint was missing off the drum area.  Looks like the original owner was one of those guys who only used the rear brake.

There's a stud with a nut on the rim, I assume its to keep something from turning inside the rim.  I wonder what kind of inner-tube I'll need?  Anyone listening who has a recommendation on inner-tubes?

Imp door latch repair

Here's my latest attempt to bring back life into a worn Imp door latch plate.  The hard steel star-wheel on the door wears away the soft potmetal of the door latch plate.  Over time grooves wear into the latch and make it impossible to latch the door without slamming it.

The first move is to put some washers behind it and move the contact point.  When this fails and the grooves just wear wider, then another solution is needed.

I then took and cleaned up the teeth of the latch plate, and even roughed them up.  This way the epoxy will stick better.  I coated the teeth with two-part epoxy and then fitted a thin stainless steel sheetmetal piece over top of the original potmetal.  This should prevent wear since the potmetal is protected and the stainless is a bit more resilient.  We'll see how it works.

Root Cause Failure Analysis

One basic precept of my mentor Russell, is that you never treat the symptom you always find the root cause and correct that.

Well, here's the root cause of my engine failure.  It seems a large chunk of the rear main bearing came loose, then got ground up and entered the oil hole in the crankshaft.  This distributed the ground up bearing material through the connecting rods.  Lovely, huh?

This can only result in replacement.  The shaft isn't too bad of shape.  It can probably be machined down nicely after I decide what replacement bearing should be bought.  The worst part is that I spent 20 minutes straight flushing the gunky particles out of the crankshaft.  I blew it out with air, put more cleaning fluid in, then flushed it again.  Still little sparkly bits of bearing were flushed out.  Eventually, I sprayed some seriously strong solvent in it and let it sit.

But that's the end of the story.  It all started with trying to get the timing gear off.  What a chore that was.  A little tension and some heat didn't budge it.  We broke the first puller, and finally succeeded with the second.  Once it started moving it was ok.  I hate to think how hard it will be to get back on.

The bores look good.  Thank goodness.



I lightly scribed an arrow on the pistons pointing front.  The stamped number on the connecting rod points to the left of the engine.



There's a small amount of rust damage to the top of the shaft that retains the half-time gear.  It pulls from the chain, so I don't think it will hurt at all.  I may polish it down a slight amount to make sure there are no high spots.



The engine case is free and clear... waiting to be cleaned.

The combustion chambers are amazingly clean.  Meaning, it didn't get any miles since the last teardown ... or it just ran really clean.

I think it just runs really clean, since the ports are clean as well.  The head gasket wasn't too messed up either.  I probably should replace it.  The bill at Stewart is going up.

Clutch Pushrod Receiver installed

I test fit the pushrod receiver onto the pressure plate, and stuck a makeshift rod in it for effect.  The receiver fit well.  I'll likely use a good epoxy and attach it permanently.  I'm still torn about using a ball bearing in this arrangement.  My Yamaha uses a ball bearing in the center of the rod.  This increases the loading on the rod to only the center.  With a Silver Steel (tool grade drill rod stock) this should not be a problem.  However, is it really needed?  The rod is SUPPOSED to turn, that's why there is a thrust bearing arrangement at the back of the gearbox where the lever pushes the rod.

I will consider this a little more.  Any commentary from those of you reading this are welcome.

Clutch Pushrod Receiver

Special thanks to my workmate Mikhail who went home last night and spun me a clutch pushrod receiver per Wilhelm's measurements and my DXF file.

All it needs is test fit... then figure a way to fasten it to the pressure plate (hopefully it will interference fit into the square hole)... put a ball bearing in the middle... figure a way to fasten that so the ball doesn't fall out, when the pushrod is pulled out the back (set screw, or center punch?)Harden it... then put it in with some grease.

Valve Timing

The chain tensioner was easy to remove.  I simply put a wrench on it, and screwed it out.  It will need new gaskets before re-assembly.

I carefully took the distributor off and laid it aside with the rest of the parts in a safe place.  I noted that the modern bolt was on the left side.  The drive pin goes UP into the hole in the crank.  Need to check the slop in that connection...  there seems to be a bit of wear, which concerns me.

I was trying to figure out the valve timing last night.  None of the marks on the crank lined up.  However, the crank did line up in the correct position with the camshaft.  It was hard to tell if it was one tooth off or not.  The next step is to get the camshaft pulley off.  Once that is off, the chain should drop down and the timing gear should pull out.  The bolt seems a bit tight and I can't hold it still to get it loose.

Armature and timing cover removed

I finally dedicated some time to taking the flywheel and armature off.  PBlaster is a great penetrating oil.  Just a few squirts and a day of waiting and everything came right off.

Well, I did have to fashion a slide hammer for the armature.  I tapped out a 7/16" bolt thread into the armature just a few threads.  Then I made this slide hammer and it came right off with a few pulls.

It here's what I found when the timing cover came off.  Not much to see, but I'll have to line up the timing marks to see how everything is supposed to go back together.  Long bolt goes in the top of the timing cover.  Why its chewed up, I don't know yet.

The seals are naturally petrified.  The timing cover seal has apparently no metal backing built into it, since it sits inside the timing cover and needs to be pried out rather than slid out the side.